Electromagnetically shiftable positive engagement clutch

Abstract

To provide an electromagnetically shiftable positive engagement clutch which can detect an engagement position by means of direct measurement.SOLUTION: A clutch includes: a shift sleeve (16) which is linearly displaceable along a shaft between an engagement position and a disengagement position; a clutch body aligned coaxially with the shaft; and a stator (26) having at least one energizable drive coil (30) for adjustment of the shift sleeve (16) along the shaft. The clutch further has a stationary sensor device (42) which is arranged adjacent to the shift sleeve (16) and includes a hall sensor and at least two magnets that magnetically enclose the hall sensor and are permanently stationary. The magnets point toward the shift sleeve (16) and have opposite polarities relative to each other. The sensor device (42) is adjacent to the shift sleeve (16) in a radial direction so as to be spaced apart therefrom by a radial gap, so that axial movement of the shift sleeve (16) is detected by the hall sensor through reduction in the radial gap.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates to an electromagnetically shiftable, positively engaging clutch. [Background technology]

[0002] Clutches are typically used to temporarily transfer torque from one shaft to another coaxial shaft without permanently connecting the two shafts. A distinction is made here between frictional engagement clutches and active engagement clutches. The present invention relates to actively engaged clutches, referred to herein as active engagement clutches. Active engagement clutches include, for example, toothed clutches and dog clutches.

[0003] Positive engagement clutches often use a displaceable shift sleeve with one or more intermeshing teeth to create positive engagement and allow torque to be transferred from one shaft to a second shaft.

[0004] The prior art discloses an electromagnetic clutch in which the shift sleeve is adjusted by a drive coil that exerts a magnetic force on the shift sleeve. In this type of clutch, the shift sleeve can be engaged with the clutch body by moving it in one direction from a disengaged position. This is called an overrunning clutch.

[0005] Additionally, double sided clutches are known in which the shift sleeve can be moved in opposite directions from a disengaged position to engage different axially spaced apart clutch bodies. DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0006] In particular, in an electromagnetically shiftable, actively engaging clutch, a controller is provided that controls the displacement of the shift sleeve via a control command. To achieve an optimal clutch operating process, the current position of the shift sleeve, also known as the engagement position, must be known. This is because, for each control command sent to the electromagnetically shiftable, actively engaging clutch, the current engagement state must first be analyzed so that the controller can query the position of the shift sleeve at any time.

[0007] In the prior art, the shift state or engagement position of the shift sleeve is determined by indirect measurements, such as the current state of the stator or the speed of the connected shaft.

[0008] Alternatively, the sensor can be integrated into the housing of the positive dog clutch, although in this case too, an indirect measurement is usually performed, for example by means of an additional actuating part, such as a displaceable part, in particular a disc, connected to the shift sleeve.

[0009] A switch can also be used to determine the end position of the shift sleeve, i.e., the engaged or disengaged position of the shift sleeve, in which case the switch is actuated by a dedicated actuating element when the shift sleeve is in the engaged position.

[0010] Instead of a switch, a displacement measurement system could also be used, which is also actuated by an additional component.

[0011] The shift sleeve position detection methods known in the prior art are characterized by indirect measurements that require scanning or actuation of additional components, making it impossible to directly and accurately detect the actual clutch engagement position and always requiring additional components.

[0012] Additionally, the position of the shift sleeve is typically sensed axially, increasing the installation space required for a positive engagement clutch.

[0013] Furthermore, the additional parts and installation space required increase the manufacturing cost of positive engagement clutches.

[0014] Furthermore, these measurement techniques often require precise calibration of the sensor to the measurement point, which is usually very complex and costly. [Means for solving the problem]

[0015] It is therefore an object of the present invention to provide an electromagnetically shiftable active engagement clutch that detects the engagement position by direct measurement, while requiring as little installation space and as few parts as possible.

[0016] This object is achieved by an electromagnetically shiftable active engagement clutch according to the present invention. The active engagement clutch includes a shift sleeve arranged to rotate integrally with a shaft and linearly displaceable along the shaft between a clutch-engaged position and a clutch-disengaged position. The active engagement clutch further includes at least one clutch body arranged coaxially with the shaft and a stator having at least one energizable drive coil for adjusting the shift sleeve along the shaft. In the clutch-engaged position, an active engagement is formed between the shift sleeve and the clutch body, thereby forming a rotational connection between the shaft and the clutch body. The active engagement clutch further includes a sensor device arranged adjacent to the shift sleeve, the sensor device including at least one Hall sensor and at least two magnets magnetically surrounding the at least one Hall sensor and permanently fixed relative to the at least one Hall sensor. The magnets are oriented toward the shift sleeve and have opposite polarities. The sensor device is radially adjacent to the shift sleeve and spaced apart by a radial gap, such that axial movement of the shift sleeve is detected by the Hall sensor via a decrease in the radial gap.

[0017] In other words, at least one Hall sensor is fixed within the magnetic field of two magnets of opposite polarity inside the clutch, radially inside the stator. The Hall sensor detects changes in radial distance from the shift sleeve, and based on this data, the controller can determine the engagement position of the shift sleeve. Because this is a direct measurement, no additional components are required, reducing manufacturing costs. Furthermore, Hall sensors are commonly used, inexpensive, and require little installation space. In particular, since the Hall sensor is radially adjacent to the shift sleeve in the axial direction, little additional installation space is required. In particular, the exact position of the shift sleeve can be detected without or independently of coil current.

[0018] Therefore, the position of the shift sleeve is determined using the Hall effect, which means measuring the change in voltage across a current conductor placed in a magnetic field. The change in the magnetic field that accompanies the displacement of the shift sleeve results in exactly this change in voltage.

[0019] The Hall sensor is magnetically surrounded by at least two magnets of opposite polarity, which prevents the influence of the magnetic field of the drive coil, which could lead to uncontrolled changes in the Hall effect. These magnets therefore serve as a magnetic shield for the Hall sensor.

[0020] Furthermore, this arrangement eliminates the need for a permanent magnet fixed to the shift sleeve, which significantly reduces manufacturing costs, as suitable permanent magnets for shift sleeves are custom-made ring-shaped parts that typically significantly increase manufacturing costs.

[0021] Preferably, the shift sleeve has an outer inclined surface that defines a detection area for the sensor device and defines a radial gap on the shift sleeve, the width of which changes during axial movement of the shift sleeve.The inclined surface formed on the outer side of the shift sleeve makes it possible to determine not only whether the shift sleeve is currently in the clutch-on or clutch-off position, but also the exact engagement position of the shift sleeve at any time.

[0022] Therefore, the portion of the shift sleeve including the ramped surface preferably corresponds to at least the required travel of the actively engaging clutch, i.e., the required shift travel, such that the decrease or increase in radial clearance caused by each movement of the shift sleeve is actively detected by the Hall sensor.

[0023] In one embodiment, the ramp surface is formed by a tapered axial edge of the shift sleeve.

[0024] Alternatively, instead of an inclined surface, the shift sleeve may be provided with steps, allowing the position of the shift sleeve to be determined in discrete steps.

[0025] In another embodiment, the sensor device includes a magnetic shorting bridge adjacent one end of the magnet to magnetically couple the magnets. Using such a shorting bridge, the magnetic flux can be redirected, i.e., increased, from one magnet to the other. This allows the Hall sensor to be better shielded from the stator's magnetic field and the signal output from the Hall sensor to be amplified, resulting in higher overall resolution.

[0026] According to a preferred embodiment, the at least two magnets are magnetically connected to one another at their ends remote from the shift sleeve by a short-circuit bridge, which further shields the Hall sensor from the magnetic field of the drive coil and effectively prevents uncontrolled changes in the Hall effect. Therefore, the short-circuit bridge is preferably made of a magnetically soft material.

[0027] In one embodiment, the short-circuit bridge is divided into a first bridge portion and a second bridge portion. The first bridge portion and the second bridge portion may be arranged such that a gap is formed between the two bridge portions, and the Hall sensor may be arranged in the gap between the first bridge portion and the second bridge portion. By arranging the Hall sensor between the two bridge portions of the short-circuit bridge, the signal is further amplified and higher resolution can be achieved compared to using a continuous short-circuit bridge.

[0028] According to a preferred embodiment, each magnet is provided at its end remote from the split short-circuit bridge with a soft magnetic material that guides the magnetic flux, amplifying the Hall sensor signal and also serves to prevent undesired changes in the Hall effect due to the magnetic field generated by the stator.

[0029] According to another embodiment, the sensor device comprises at least two Hall sensors, each associated with a magnet adjacent to the corresponding Hall sensor, which also shields the Hall sensors from the magnetic field of the drive coil, so that uncontrolled changes in the Hall effect do not distort the measurements of the Hall sensors.

[0030] Preferably, the Hall sensors are positioned adjacent to the shift sleeve-side ends of the corresponding magnets and between the shift sleeves. This allows the distance between the Hall sensors and the shift sleeve to be kept as short as possible, ensuring the most accurate measurement possible, since measurement accuracy decreases as the distance between the Hall sensors and the shift sleeve increases. High-precision Hall sensor resolution is particularly important for electromagnetically shiftable, actively engaged clutches, where the clutch control stroke is on the order of a few millimeters.

[0031] In one embodiment, the at least one Hall sensor is mounted either directly to the circuit board or via at least two magnets, which allows for easy fixation of the sensor device and allows for direct transmission of the sensor signal to the controller.

[0032] The magnets are placed parallel to each other and / or on the same side of the circuit board containing the Hall sensors. Parallel placement of the magnets ensures that the magnets are aligned with exactly opposite polarities, providing the necessary magnetic flux for the shield and ensuring accurate measurements.

[0033] The magnet may be a permanent magnet or an electromagnet.

[0034] According to one embodiment, at least two sensor devices are provided, which are arranged offset from one another in the circumferential direction, so that uneven displacement of the shift sleeve, for example due to tilting of the shift sleeve, can be detected early, so that the shift sleeve can be controlled to counteract the tilting movement or a quick disengagement and reengagement of the clutch can be performed in a short time.

[0035] According to one embodiment, the sensor device is housed in a sensor housing, which is attached to the stator housing.

[0036] Preferably, only one clutch body is connected to the shift sleeve, and the sensor device is arranged on the axial side of the shift sleeve away from the clutch body, which eliminates the need to arrange the sensor between the clutch body and the shift sleeve, or immediately adjacent to or above the clutch body, thereby avoiding installation space issues. [Brief explanation of the drawings]

[0037] [Figure 1] FIG. 1 is a cross-sectional view of an electromagnetically shiftable, active engagement clutch according to the present invention with the shift sleeve in a disengaged position. [Figure 2] FIG. 2 is a detailed view of the vicinity of the sensor device of the active engagement clutch shown in FIG. [Figure 3] FIG. 3 is a detailed cross-sectional view of the sensor device. [Figure 4]FIG. 4 shows a further embodiment of a positive engagement clutch according to the invention in cross section together with two sensor devices. [Figure 5] FIG. 5 is a top view of the active engagement clutch shown in FIG. [Figure 6] FIG. 6 is a detailed perspective view of an alternative sensor device. [Figure 7] FIG. 7 is a schematic diagram of the sensor device shown in FIG. [Figure 8] FIG. 8 is a schematic diagram of a further alternative configuration of the sensor device. DETAILED DESCRIPTION OF THE INVENTION

[0038] Further advantages and features of the present invention will become apparent with reference to the following description and accompanying drawings.

[0039] FIG. 1 illustrates an electromagnetically shiftable, positively engageable clutch 10 that functions to open and close a first shaft 12 and a second shaft 14 that is coaxially disposed therewith.

[0040] The positively engageable clutch 10 shown in FIG. 1 is an electromagnetic toothed clutch having radially inwardly and radially outwardly projecting, intermeshing teeth.

[0041] However, the electromagnetically shiftable, positively engaging clutch 10 may be any other type of toothed clutch, it being only important that the connection be established by positive engagement.

[0042] The electromagnetically shiftable positive engagement clutch 100 includes a shift sleeve 16 having first teeth 18 disposed laterally about its circumference.

[0043] Furthermore, a shift sleeve 16 is disposed on the first shaft 12 for unitary rotation and is axially adjustable between a clutch-engaged position and a clutch-disengaged position along teeth 19 connecting the shaft 12 and the shift sleeve 16. Figure 1 shows the shift sleeve 16 in the disengaged position.

[0044] The second shaft 14 has a single clutch body 20 associated therewith and coupled to the second shaft 14 for rotation therewith.

[0045] The clutch body 20 includes second teeth 22 arranged along the outer periphery of the clutch body 20. Furthermore, the clutch body 20 is arranged coaxially with the first shaft 12.

[0046] However, it is also conceivable that the clutch body 20 forms a part of the second shaft 14 and is formed integrally with the second shaft 14 .

[0047] The first toothing 18 and the second toothing 22 form a clutch tooth row 24 that serves to provide a positive engagement between the shift sleeve 16 and the clutch body 20 when the shift sleeve 16 is in the engaged position.

[0048] The clutch tooth row 24, which is made up of the first toothing 18 and the second toothing 22, may have undercuts on at least the teeth of the first toothing 18 and / or the teeth of the second toothing 22. The undercuts are configured so that when the shift sleeve 16 is in the clutch-engaged position and torque is applied to the active engagement clutch 10, the circumferential force is converted into an axial displacement force, causing the shift sleeve 16 to be displaced further toward the clutch body 20. This can be achieved, for example, by the undercuts widening in a wedge shape, which creates a wedge effect in the direction of the clutch-engaged position when torque is transmitted.

[0049] Additionally, a stator 26 is provided that includes a stator housing 28 and a drive coil 30 at least partially contained within the stator housing 28 .

[0050] The stator housing 28 includes a housing pot 32 that extends around the circumference of the drive coil 30 and along the front face of the drive coil 30 .

[0051] The stator housing 28 further includes a housing ring 34 that extends around the circumference of the drive coil 30 and also extends across the front of the drive coil 30 opposite the housing pot 32 .

[0052] The drive coil 30 is used to linearly adjust the shift sleeve 16 along the first shaft 12 to the clutch body 20 toward an engaged position.

[0053] Alternatively, the drive coil 30 may be used to adjust the shift sleeve 16 along the first shaft 12 toward the release position. The adjustment of the shift sleeve 16 is performed by utilizing a magnetic force acting on the shift sleeve 16 when the drive coil 30 is energized. To return the shift sleeve to the release position, a resilient spring unit 40 is provided, and the resilient spring unit 40 connects the shift sleeve 16 to the first shaft 12 so as to be displaceable in the axial direction.

[0054] The elastic spring unit 40 is disposed between the shift sleeve 16 and the first shaft 12, and when the shift sleeve 16 moves axially relative to the first shaft 12 toward the clutch engagement position, the elastic spring unit 40 is compressed. This generates a restoring force that the first elastic spring unit 40 exerts on the shift sleeve 16.

[0055] This restoring force acts against the magnetic force of the drive coil 30 .

[0056] The elastic spring unit 40 is arranged in a recess in the shaft 12 and presses axially against the wall of the shaft on the one hand and against a disk 41 fixed to the shift sleeve 16 on the other hand.

[0057] Therefore, the elastic spring unit 40 is housed in a space surrounded by the first shaft 12 on the radial inside and the shift sleeve 16 on the radial outside.

[0058] The spring unit 40 may preferably be a wave spring or wave spring assembly. As can be particularly seen in the detailed view of Figure 2, the first embodiment of the active engagement clutch 10 shown here further includes a sensor device 42.

[0059] As can be seen particularly in FIG. 3, the sensor device 42 comprises at least two Hall sensors 44 and two magnets 46 that magnetically surround and are immediately adjacent to the Hall sensors 44 .

[0060] The magnet 46 may be a permanent magnet or an electromagnet and is used to provide a stable magnetic field to the Hall sensor 44 .

[0061] For this purpose, the magnets 46 each have one end facing the shift sleeve 16 and are permanently fixed or attached to the Hall sensor 44. To ensure the best possible magnetic flux, one magnet 46 faces the shift sleeve 16 with its positive pole and the other magnet 46 faces the shift sleeve 16 with its negative pole, i.e., they have opposite polarities.

[0062] In the exemplary embodiment shown, each Hall sensor 44 is provided with a corresponding magnet 46. As previously mentioned, each magnet 46 is adjacent to a corresponding Hall sensor 44.

[0063] In this case, the Hall sensor 44 is disposed at the end of the corresponding magnet 46 on the shift sleeve 16 side, and the Hall sensor 44 is disposed between the corresponding magnet 46 and the shift sleeve 16 .

[0064] As shown in FIG. 2, the sensor device 42 is housed in a sensor housing 48 that is fixed laterally to the stator housing 28.

[0065] The sensor housing 48 may be secured to the stator housing 28 by, for example, screws 50 .

[0066] As shown particularly clearly in FIG. 3, each of the two Hall sensors 44 is attached to the circuit board 52 via one of the magnets 46 .

[0067] Here, each Hall sensor 44 is fixed to the end of the magnet 46 facing the shift sleeve 16 side.

[0068] Locating the Hall sensor 44 between the magnet 46 and the shift sleeve 16 is particularly advantageous because the measurement accuracy of the Hall sensor 44 decreases as the distance increases. Therefore, the Hall sensor 44 should be located as close as possible to the shift sleeve 16 so that the engagement position of the shift sleeve 16 can be measured as accurately as possible.

[0069] 3, the magnets 46 are not only arranged with opposite polarities, but also parallel to each other, ensuring a defined magnetic flux between the magnets 46.

[0070] Furthermore, the two magnets 46 are located on the same side of the circuit board 52 .

[0071] The sensor device 42 is radially fixed to the stator housing 28 at a radial gap from the shift sleeve 16 so that the engagement position of the shift sleeve 16 can be determined. Axial movement of the shift sleeve 16 either decreases or increases the radial gap depending on the direction of movement of the shift sleeve 16, as described below, resulting in a change in the magnetic field detected by the Hall sensor(s) 44.

[0072] In order to distinguish between the clutch engaged and clutch disengaged positions, as well as to be able to determine the exact engaged position of the shift sleeve 16 at any time, the shift sleeve 16 is provided with an inclined surface 54 on the outside opposite the sensor device 42. The inclined surface 54 forms a detection area for the sensor device 42 and defines a radial clearance in a portion of the shift sleeve 16.

[0073] Preferably, the ramp surface 54 is formed by a tapered axial edge of the shift sleeve 16 .

[0074] As shown in FIG. 1, since only one clutch body 20 is attached to the shift sleeve 16, the sensor device 42 can be located on the side of the shift sleeve 16 axially away from the clutch body 20.

[0075] The function and operation of the active engagement clutch 10 and the detection of the engagement position of the shift sleeve 16 by the sensor device 42 will now be described.

[0076] The initial state here is constituted by the disengaged position of the shift sleeve 16, as shown in FIG.

[0077] Here, there is no active engagement between the first teeth 18 of the shift sleeve 16 and the second teeth 22 of the clutch body 20 .

[0078] In this disengaged open state, the shift sleeve 16 is held by the elastic spring unit 40 unless an external force exceeding the spring force of the spring unit 40 acts on the shift sleeve 16 .

[0079] This is also referred to as a "normally open" positive engagement clutch 10.

[0080] As long as the shift sleeve 16 is in the release position, the radial gap does not change and the Hall sensor 44 of the sensor device 42 does not detect a signal.

[0081] To move the shift sleeve 16 from the release position toward the clutch body 20, it is first necessary to apply a sufficient voltage to the drive coil 30. The energization of the drive coil 30 is controlled by a controller 56. The controller 56 controls the clutch operation process and also processes signals from the sensor device 42 (see FIG. 5).

[0082] Thus, the controller 56 is connected to both the drive coil 30 and the sensor device 42, and the controller 56 and the sensor device 42 are connected to each other at least in terms of signal transmission.

[0083] The connection between the controller 56 and the sensor device 42 is preferably made via the circuit board 52, and the sensor device 42 may be connected to the controller 56 via cables, wires, and / or plugs.

[0084] When the drive coil 30 is energized, a magnetic flux is generated, and a magnetic force acts on the shift sleeve 16 in the direction of the clutch body 20 .

[0085] When the amount of magnetic force exceeds the amount of spring force acting on the shift sleeve 16 by the spring unit 40 , the shift sleeve 16 moves toward the clutch body 20 .

[0086] Due to the inclined surface 54 on the outside of the shift sleeve 16, this movement of the shift sleeve 16 reduces the radial gap between the sensor device 42 and the shift sleeve 16, thereby causing a change in the distance between the Hall sensor 44 and the inclined surface 54.

[0087] Movement of the shift sleeve 16 and the resulting reduction in radial gap changes the magnetic field, causing a change in the Hall voltage from which the engagement position of the shift sleeve 16 can be inferred.

[0088] As a result, the shift sleeve 16 is in the clutch engaged position. When the drive coil 30 is energized, a magnetic holding force acts on the shift sleeve 16.

[0089] Preferably, the ramp 54 corresponds to the required travel distance, or shift travel distance, of the shift sleeve 16 so as to be able to actively distinguish any position of the shift sleeve 16 between the clutch disengaged and clutch engaged positions.

[0090] In the clutch engaged position, the first toothing 18 and the second toothing 22 mesh with each other, creating a positive mesh between the shift sleeve 16 and the clutch body 20 .

[0091] As already mentioned, the first toothing 18 and / or the second toothing 22 may be provided with an undercut axially and transversely in the direction of the clutch engagement position.

[0092] When the two tooth portions 18, 22 are provided with undercuts, torque transmission between the clutch body 20 and the first shaft 12 generates a force on the shift sleeve 16 in the direction of the clutch engagement position, i.e., toward the clutch body 20, due to the undercuts and the wedge effect that occurs between the contacting teeth.

[0093] Here, the force acting on the shift sleeve 16 depends greatly on the shape of the undercuts of the tooth portions 18, 22 and the torque acting thereon.

[0094] While the shift sleeve 16 is in the clutch-engaged position, the radial gap does not change, and therefore the Hall sensor 44 cannot detect a change in the Hall voltage.

[0095] To return the shift sleeve 16 to the clutch release position, it is first necessary to reduce or cancel the magnetic force generated by energizing the drive coil 30.

[0096] When the amount of magnetic force acting on the shift sleeve 16 becomes less than the amount of restoring force generated by the elastic spring unit 40 acting on the shift sleeve 16, the shift sleeve 16 returns from the clutch-engaged position to the clutch-disengaged position.

[0097] In this state, the shift sleeve 16 is held in place by the spring force of the elastic spring unit 40 .

[0098] As the shift sleeve 16 moves from the clutched position to the clutch disengaged position, the ramps 54 on the outside of the shift sleeve 16 increase the radial gap, and a Hall voltage is also detected due to the changing magnetic field.

[0099] In an embodiment not shown, the sensor device 42 comprises a magnetically continuous short-circuit bridge that engages the ends of the magnets 46 remote from the shift sleeve 16 and magnetically connects and couples the magnets 46 together.

[0100] The magnetic flux between the at least two magnets 46 is directed by this shorting bridge, surrounding the Hall sensor 44 with a stronger magnetic field. In this way, the Hall sensor 44 is effectively shielded from the magnetic field generated by the drive coil 30, preventing undesired changes in the Hall effect due to the magnetic field of the drive coil 30.

[0101] Therefore, the shorting bridge is preferably made of a magnetically soft material, such as a ferromagnetic metal or metal oxide.

[0102] Figure 4 shows a further embodiment of the active engagement clutch 10. This embodiment differs from the embodiment shown in Figures 2 and 3 in that two sensor devices 42 are provided.

[0103] The design of the sensor device 42 and the detection of the position of the shift sleeve 16 remain unchanged.

[0104] As shown in FIG. 4, the sensor devices 42 are arranged offset from one another in the circumferential direction, for example, by 180 degrees.

[0105] By using at least two sensor devices 42 to determine the engagement position of the shift sleeve 16, it is possible to detect not only the current engagement position but also whether the shift sleeve 16 is slightly tilted.

[0106] If so, the controller 56 can output appropriate control commands to reorient the shift sleeve 16 perpendicular to the first shaft 12 .

[0107] The axial arrangement of the sensor device 42 is apparent from FIG.

[0108] 6 and 7 show a further embodiment of a sensor device 42 which can also be used to determine the engagement position of the shift sleeve 16.

[0109] The sensor device 42 shown here includes a magnetic split shorting bridge 58 that is magnetically coupled to the magnets 46 and adjacent the end of each magnet 46 remote from the shift sleeve 16.

[0110] As previously mentioned, such a magnetic shorting bridge 58 serves to direct the magnetic flux of the magnetic fields of the two magnets 46 and shield the Hall sensor 44 or sensors 44 from the magnetic field of the drive coil 30, which could cause uncontrolled changes in the Hall effect.

[0111] Therefore, the signal detected by the Hall sensor 44 can be amplified by using the shorting bridge 58 to achieve higher resolution.

[0112] In the embodiment shown in FIGS. 6 and 7, the shorting bridge 58 is divided into a first bridge section 60 and a second bridge section 62.

[0113] Each bridge portion 60 , 62 is associated with one of the magnets 46 and is attached to the side remote from the shift sleeve 16 so that each bridge portion 60 , 62 extends to the other magnet 46 .

[0114] Here, the bridge portions 60, 62 are arranged so that a gap is formed between them, and the Hall sensor 44 is disposed in the gap.

[0115] By using such a split short-circuit bridge 58, only one Hall sensor 44 is required.

[0116] In the illustrated embodiment, in addition to the shorting bridge 58, a magnetically soft material 64 is optionally provided at the end of the magnet 46 remote from the split shorting bridge 58.

[0117] This magnetically soft material 64 may be the same magnetically soft material used in the shorting bridge 58 .

[0118] Figure 8 shows an embodiment of the sensor device 42 which essentially corresponds to the sensor device 42 of Figures 6 and 7. The difference is that in the embodiment of Figure 8, the end of the magnet 46 remote from the short-circuit bridge 58 is not provided with a magnetically soft material 64.

[0119] Of the sensor devices 42 shown in FIGS. 6 to 8, two sensor devices 42 are provided to correct the inclination of the shift sleeve 16.

[0120] Although the figures illustrate a positively engageable clutch 10 having one clutch body 20, the sensor device 42 can also be installed on both sides of the positively engageable clutch 10. To this end, the ramp 54 on the shift sleeve 16 can be enlarged to cover both directions of movement of the shift sleeve 16. Alternatively, a V-shaped groove can be provided on the outer periphery of the shift sleeve.

[0121] Alternatively, the active engagement clutch 10 may include two sensor devices 42 each attached to one axial side of the shift sleeve 16. For this purpose, the shift sleeve 16 must have an inclined surface 54 on each side that defines the detection area of ​​each sensor device 42.

[0122] The illustrated positive engagement clutch is unique in that it does not require any additional components to be attached to the shift sleeve 16 to sense the position of the shift sleeve 16.

Claims

1. a shift sleeve (16) disposed on the shaft (12) so as to rotate integrally with the shaft (12) and linearly displaceable along the shaft (12) between a clutch-engaged position and a clutch-disengaged position; At least one clutch body (20) arranged coaxially with the shaft (12); a stator (26) having at least one energizable drive coil (30) for adjusting the shift sleeve (16) along the shaft (12); a sensor device (42) disposed adjacent to the shift sleeve (16) and including at least one Hall sensor (44) and at least two magnets (46) magnetically surrounding the at least one Hall sensor (44) and permanently fixed relative to the at least one Hall sensor (44); Equipped with In a clutch engaged position, active engagement between the shift sleeve and the clutch body (20) creates a rotational connection between the shaft (12) and the clutch body (20); The magnets (46) are oriented toward the shift sleeve (16) and have opposite polarities; The sensor device (42) is radially adjacent to the shift sleeve (16) and spaced apart by a radial gap, and axial movement of the shift sleeve (16) is detected by the Hall sensor (44) via changes in the radial gap.

2. the shift sleeve (16) has an inclined surface (54) on the outside facing the sensor device (42), the inclined surface (54) forming a detection area of ​​the sensor device (42) and defining the gap on the shift sleeve (16) side; 2. The electromagnetically shiftable, active engagement clutch (10) of claim 1, wherein said ramped surface (54) varies the width of said gap during axial movement of said shift sleeve (16).

3. 3. The electromagnetically shiftable, positively engageable clutch (10) of claim 2, wherein said ramp surface (54) is defined by a tapered axial edge of said shift sleeve (16).

4. 4. The electromagnetically shiftable active engagement clutch (10) of claim 1, wherein the sensor device (42) comprises a magnetic shorting bridge (58) adjacent one end of the magnet (46) and magnetically coupling the magnet (46).

5. 5. The electromagnetically shiftable active engagement clutch (10) of claim 4, wherein at least two of the magnets (46) are connected to one another at their ends remote from the shift sleeve (16) by the magnetic shorting bridge (58).

6. 6. The electromagnetically shiftable active engagement clutch (10) according to claim 4 or 5, characterized in that the magnetic shorting bridge (58) is divided into a first bridge portion (60) and a second bridge portion (62), the first bridge portion (60) and the second bridge portion (62) are arranged so as to create a gap between the two bridge portions (60, 62), and the Hall sensor (44) is arranged in the gap between the first bridge portion (60) and the second bridge portion (62).

7. 7. The electromagnetically shiftable, active engagement clutch (10) of claim 6, wherein each of the magnets (46) comprises a magnetically soft material (64) at an end remote from the magnetic shorting bridge (58).

8. 6. The electromagnetically shiftable active engagement clutch (10) of claim 1, wherein the sensor device (42) comprises at least two Hall sensors (44), each of which is connected to a magnet (46) adjacent to the corresponding Hall sensor (44).

9. 9. The electromagnetically shiftable active engagement clutch (10) of claim 8, wherein the Hall sensors (44) are disposed adjacent to the shift sleeve (16) side ends of the corresponding magnets (46) and between the ends and the shift sleeve (16).

10. 10. The electromagnetically shiftable active engagement clutch (10) of claim 1, wherein at least one of the Hall sensors (44) is mounted to a circuit board (52) either directly or via one of the at least two magnets (46).

11. 11. An electromagnetically shiftable active engagement clutch (10) according to any one of claims 1 to 10, characterized in that the magnets (46) are arranged in parallel and / or are provided on the same side of a circuit board (52) that also includes the Hall sensor (44).

12. 12. An electromagnetically shiftable, active engagement clutch (10) according to any one of claims 1 to 11, characterized in that the magnet (46) is a permanent magnet or an electromagnet.

13. 13. An electromagnetically shiftable active engagement clutch (10) according to any one of claims 1 to 12, characterized in that at least two of the sensor devices (42) are provided, and the at least two of the sensor devices (42) are arranged offset from one another in the circumferential direction.

14. 14. The electromagnetically shiftable active engagement clutch (10) of claim 1, wherein the sensor device (42) is housed in a sensor housing (48), and the sensor housing (48) is attached to the stator housing (28).

15. 15. The electromagnetically shiftable active engagement clutch (10) of claim 1, wherein only one clutch body (20) is connected to the shift sleeve (16), and the sensor device (42) is provided at an axial end of the shift sleeve (16) remote from the clutch body (20).

Images